Supporters of Canada-based preacher Tahir-ul-Qadri climb on a crane to remove containers to march towards the parliament during an anti-government march in Islamabad on August 19, 2014. Pakistan on August 19 sent troops to boost security in Islamabad's government district, as opposition politician Imran Khan and a populist cleric led protesters marching on parliament in a high-stakes bid to depose the prime minister. Khan, the former cricket star who leads the Pakistan Tehreek-e-Insaaf (PTI) party, and preacher Tahir-ul-Qadri say last year's general election was rigged and have demanded Prime Minister Nawaz Sharif resign. AFP PHOTO / FAROOQ NAEEMFAROOQ NAEEM/AFP/Getty Images

Photo: Farooq Naeem, AFP/Getty Images

Supporters of Canada-based preacher Tahir-ul-Qadri climb on a crane...

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Supporters of Canada-based preacher Tahir-ul-Qadri march towards the parliament during an anti-government march in Islamabad on August 19, 2014. Pakistan on August 19 sent troops to boost security in Islamabad's government district, as opposition politician Imran Khan and a populist cleric led protesters marching on parliament in a high-stakes bid to depose the prime minister. Khan, the former cricket star who leads the Pakistan Tehreek-e-Insaaf (PTI) party, and preacher Tahir-ul-Qadri say last year's general election was rigged and have demanded Prime Minister Nawaz Sharif resign. AFP PHOTO / FAROOQ NAEEMFAROOQ NAEEM/AFP/Getty Images

Photo: Farooq Naeem, AFP/Getty Images

Supporters of Canada-based preacher Tahir-ul-Qadri march towards...

Image 3 of 3

Supporters of Pakistan's cricketer-turned-politician Imran Khan try to get past shipping containers place by authorities to block their march to the Parliament in Islamabad, Pakistan, Tuesday, Aug. 19, 2014. Tens of thousands of anti-government protesters armed with wire cutters and backed by cranes marched on Pakistan's parliament Tuesday, removing barriers blocking them from soldiers guarding the seat of the country's government. (AP Photo/B.K. Bangash)

ISLAMABAD -- Tens of thousands of protesters armed with wire cutters and backed by cranes broke through barriers protecting Pakistan's parliament and other government buildings Tuesday night, demanding the country's prime minister resign.

Government authorities had warned they would not allow protesters to enter Islamabad's "Red Zone," but the demonstrators met no immediate resistance from police or the hundreds of troops guarding the buildings.

Wearing masks and carrying makeshift shields, they hammered through barbed wire and locks connecting shipping containers that had been erected as a barrier around the zone, which also holds the president's and prime minister's ceremonial homes and many diplomatic posts.

Demanding the resignation of Prime Minister Nawaz Sharif, they shouted, "Go, Nawaz, go!" Excited young men and women made V-for-victory signs.

A government minister, Saad Rafiq, said the prime minister allowed the protesters to enter the sensitive area to avoid bloodshed.

The Pakistani army warned the protesters against entering parliament or any other installation. It called on all sides to resolve the situation through discussion.

Men, women and children took part in the protest by some 30,000 supporters of opposition candidate Imran Khan and antigovernment cleric Tahir-ul-Qadri.

Both men have called on Sharif to step down over allegations of fraud in last year's election. Sharif has refused and ordered the soldiers out into the streets, the first such military deployment in the capital under any civilian government in Pakistani history.

Two Pakistani security officials said 700 troops had been deployed to guard the Red Zone. They spoke on condition of anonymity because they were not allowed to speak publicly about troop movements. An additional 30,000 members of the country's security forces were also deployed in the capital, authorities said.

The demonstrators have camped out in Islamabad in two rallies since last week. Khan and Qadri have vowed to keep up the sit-ins until Sharif resigns.

Khan said Tuesday that his supporters would make a "Tahrir Square" outside parliament, referring to the square in Egypt where mass protests in 2011 brought down President Hosni Mubarak.